Oh Ji Ho burst onto the television scene in 2001 with a roll in KBS drama, Cool. Prior to his work on Cool, he had small parts in two films, KKA in 1998 and La Belle in 2000. Since his start, he has become one of the “it” actors of South Korea. In 2004 he won a KBS Drama Award for Best Supporting Actor in a Drama, for his work on Second Proposal. He also received two awards in 2006 for his work on Couple of Trouble, and again in 2010 for his work on Chuno.

Oh Ji Ho's popularity grew when many of his Korean dramas were exported abroad, capturing the attention of international audiences. Currently he is at work on The 3rd Hospital, a medical drama that focuses on the conflict between western and eastern medicine.

In 2007, Oh Ji Ho drew media attention and prompted a serious discussion about personal privacy when the actor’s girlfriend of two years committed suicide shortly after their relationship ended.